The present invention relates to automatic fire protection systems and more particularly to concealed sprinkler head assemblies.
Various forms of automatic fire protection systems are available. Wet pipe systems include a main water supply and a plurality of branches. Pendent type automatic sprinkler heads are connected to the branches of the piping system along the ceiling of areas which are to be protected. Each automatic sprinkler head includes a body defining a nozzle or orifice, an arm structure and a deflector positioned opposite the nozzle. A plug or pip cap is held in the nozzle by a thermal trigger. The trigger may be a fusible link device or a glass bulb. When a predetermined temperature is reached, the bulb bursts or the link fuses thereby releasing the cap. Water flowing from the orifice strikes the deflector forming a uniform spray pattern to extinguish o control the fire.
Automatic fire protection systems of the above type are used in many environments including factories, warehouse facilities, offices, motels, hotels, residents and hospitals. In certain applications such as offices, hotels and the like, aesthetics are important. Proposals have been made to conceal each sprinkler head at the point where it penetrates openings formed in the ceiling. Concealed sprinkler head assemblies generally include an enclosure or mounting base and a cover plate which engages the ceiling and conceals the sprinkler head opening and the head assembly itself. The cover is typically attached to the enclosure or the sprinkler head assembly by a fusible link or meltable solder. Some of the prior devices use springs to secure or retain the cover plate in position or to eject the plate from the assembly when a predetermined temperature is reached. The fusible solder is selected so that the cover plate is released at a temperature just below that which would result in actuation of the sprinkler head. Should the springs, fusible links or solder break, the entire assembly may need to be replaced. The prior assemblies ar fragile and present problems with manufacture, assembly, installation and service.